The value of these stickers has probably declined significantly since that article was written, as the stickers are only valid until July 1, 2011.
A few years ago, my boss (CEO) at my last company bought a Prius at a premium for this reason so he could use the carpool lanes during rush hour. The populist/progressive in me thinks that it isn't "fair" that the rich can pay for faster commutes, but the truth is that he probably created many times more wealth than the several thousand dollar sticker premium by having an extra 30-60 minutes of productive work every day.
Carpool lanes work better in this regard. For example, on 93N heading into Boston, you can use 93N for free. If you have at least 2 people in the car (and I think hybrids and EVs are allowed as well), you can use the carpool lane. However, if you were almost always by yourself, but could pay $2000/year to get a placard to drive in the carpool lane, people would certainly pay it. Motorists without passengers are not required to pay to drive on 93N, however any motorist willing to pay ~$8/workday for the convenience therefore has the option -- that may even exclude the rich, just those who live far enough away from Boston and commuter rail stations where they need the drive (or feel the need to) and are willing to pay for a shorter commute time.
Actually, the more I think about this, the more I like it. If you are actively working towards eliminating congestion by carpooling, you still get it gratis. If you're reducing emissions by driving an EV or Hybrid, you get it gratis until that allowance sunsets, because you're making a positive impact with your vehicle choice. Yet if you're willing to just pay... hey, we'll let you in too, so that money can go towards improving something. I like this. I'm trying to find how anyone loses with this idea, because you can still use the four lanes on 93 like anyone else does for free.
People didn't like the idea because they would be "Lexus lanes" giving special privileges to the rich. Scott Adams is right that if we really want to solve the budge problems we may need to accept that the people who can help the most may need some sort of special privileges.
Because no-bid contracts, not going to jail when they commit crimes, real education for their kids, not living in crime zones, food that isn't poison, actual health care, living an extra three years, etc. aren't enough already.
It will only change during an actual complete crash of the value of money. And even then it's not guaranteed, because they will still have access to an extensive network of influential people, while "we" won't.
I'd speculate that the vast majority of these benefits are given to government workers, not to the rich. Any government worker with a union has a no-bid contract (it's illegal for competitors to underbid him), and you can find plenty of videos on youtube of cops committing crimes they get away with [1].
[1] Occasionally they are disciplined with a paid vacation.